I came to the Apple Store to shop for a bluetooth keyboard for my iPad. I was surprised to find only this one product. I've got nothing against our Japanese friends, but I have no use whatsoever for Japanese characters on a keyboard. Is this the only way Apple now markets this product? I once owned a non-Japanese model of this very keyboard, but I left the batteries in it too long. Battery leakage ruined it, and I'd like to replace it.

Yes. It's actually very simple. You don't have to do any changes to your mac at all. I recently bought a macbook pro outside of Norway, and I simply press [alt+'] for æ, [alt+o] for ø and [alt+a] for å. It takes a couple of days to get used to, but it's very simple instead of changing the whole layout, because that messes with a lot of special characters. I simply put a tape on a,o,' and alt/option with æøå.
I hope you find this helpful!

When placing order with Apple online I am given three English keyboard options e.g. Uk Engish, International English and Us English. I live in Ireland so which do I decide on. I would assume that the International English is going to have a Euro Symbol € but it does not.

Yes. All bluetooth keyboards disconnect each time you turn them off, then must reconnect when turned back on.
You don't need to do anything, however. It will automatically reconnect within a few seconds of turning on.